It might be over 50 years since the US passed the Equal Pay Act, but women still get paid less than men – in many cases for doing the same work. And even if you’re a World-Cup winning athlete, that’s no different.

But last week, five members of the US women’s soccer team (or football, for the rest of the world) decided it was time to take a stand, and have filed a wage-discrimination action against the US Soccer Federation. One of the claimants, goalkeeper Hope Solo, explained why they acted: “We are the best in the world … and the men’s team get paid more to just show up than we get paid to win major championships.”

So just how big is soccer’s gender pay gap?

Numbers don’t lie

Pretty big. It’s hard to make exact comparisons, because as the US Soccer Federation pointed out in a statement, the pay is structured differently. But as this chart from Business Insider shows, even if you only take into account World Cup prize money, the difference is enormous.

So while the US men’s team got knocked out before even making it to the 2014 World Cup quarter finals, they still took home significantly more money than the victorious women’s team.

“We got a $1.8 million dollar bonus for winning the World Cup, and we had to disburse it among the 23 players. And then we piece out some bonuses for our support staff who don’t get paid a whole bunch. The men, for losing, got $8 million to share among the players, and they also received millions of dollars for every point they won in the World Cup. We got paid nothing per point in group play. We got paid nothing for making it into the knockout round. We basically didn't get a bonus until we won the entire thing, which is incredibly difficult, and that bonus was quite a bit less than what the men got,” Hope Solo explained in an interview after the tournament.

There’s not a whole lot the US Soccer Federation can do about World Cup prize money, which is determined by FIFA. The international federation has itself been called out for sexism in the past – and not just because of the gender pay gap. Back in 2004, for example, former FIFA chief Sepp Blatter caused outrange when he suggested women’s soccer might be more popular if the players wore tighter shorts.

That said, while the US Soccer Federation might not set World Cup pay, the wage gap runs much deeper, as the New York Times shows in these infographics. Even taking into account the different pay structures, the men’s team would get more money for losing all 20 of the friendlies they play each year than the women would for winning all theirs.

It’s not the first time the issue of wage equality has come up in sport. And every time it does, the same excuses get rolled out: women’s sport isn’t as exciting or gruelling, which means fewer people follow it. For that reason, it’s less lucrative, so it’s only fair that women get paid less.

But should disparities in revenue or physical strenuousness be an excuse? Not according to the likes of tennis superstar Venus Williams, who campaigned for equal pay at Wimbledon. By paying female tennis players less than their male counterparts, Wimbledon “devalued the principle of meritocracy and diminished the years of hard work that women put into becoming professional tennis players,” Williams wrote in an Op-Ed.

Wimbledon winner Andy Murray agrees: “Men’s tennis has been lucky over the last nine or 10 years with the players they’ve had. That’s great, but the whole of tennis should capitalize on it, not just the men’s game,” he said last month to justify equal pay in the sport.

But even if you don’t buy that argument, it’s still hard to justify the huge pay gap between male and female soccer players in the US. That’s because unlike in most countries, the women’s national team is perhaps as widely followed as the men’s. When they lifted the World Cup trophy for the third time last year, the women’s team smashed all viewership records for a soccer match in the US: 26.7 million Americans tuned in.

Image: Noah K. Murray-USA TODAY Sports

As a result of its success and popularity, women’s soccer is raking in the cash. It’s just that the stars aren’t seeing much of it, whether that be in wages or investment. “In the US, there is substantially more financial investment in the men’s team and, by comparison, there is almost nothing to show for it,” Hampton Dellinger, an attorney who has represented the players on other issues, was quoted as saying in New York Daily News.

But for some, the pace of change isn’t fast enough. In fact, executives at FIFA have said it’s a long way off. “The comparison between the prize money of the men’s World Cup in Brazil to the women’s World Cup in Canada is not even a question I will answer because it is nonsense,” former FIFA secretary-general Jerome Valcke said two years ago. “We are still another 23 World Cups before potentially women should receive the same amount as men.” As the tournament is played every four years, that’s another 92 years before women can hope to win the same prize money.

The US women’s team refuses to wait that long. “We have been quite patient over the years with the belief that the federation would do the right thing and compensate us fairly,” said one of the claimants, Carli Lloyd. As Hope Solo has pointed out, it's not about getting exactly the same as the men's team; but it is about being fairly compensated for their success: "When we push for equality, we don't want the exact same thing. We just want it more balanced."

Where next?

The five soccer players who filed the complaint have an uphill legal battle, according to Michael LeRoy, a lecturer in collective bargaining and sports at the University of Illinois. “They have to prove equality of work and market conditions, and it’s such a rigid legal requirement,” he told the New York Times.